1. Field of the Invention
The present invention generally relates to a transistor circuit layout structure. Specific words, the present invention is directed to a transistor circuit layout structure which is capable of accommodating more circuits to control transistors in addition to bit lines and word lines.
2. Description of the Prior Art
A transistor structure is a metal oxide semiconductor (MOS) which includes a gate as well as at least two sets of doped regions, respectively serving as a drain or a source. A metal oxide semiconductor transistor controls the transistor to switch on or off by a word line which is electrically connected to the gate. The source of the metal oxide semiconductor is electrically connected to a capacitor to form a memory structure unit, called a dynamic random access memory. In the dynamic random access memory, the drain is electrically connected to a bit line to form a current path, and to achieve the purposes of data storage or input through a storage node which is electrically connected to a capacitor via the source.
In the current dynamic random access memory processes, the capacitors are usually designed to be either a stacked capacitor which is stacked on the substrate surface, or a deep trench capacitor which is buried in the substrate. No matter what kind of the dynamic random access memory is involved, there is only one gate which is in charge of controlling the switch on or off of the gate channel which is buried in the substrate.
With the trends toward miniaturization of electronic products, the design of the dynamic random access memory elements must meet the requirements of high-integration and high density. In order to promote the dynamic random access memory devices to have good performance, the possible leak current should be reduced to become as low as possible. In view of this, a new transistor circuit layout structure is still needed to accommodate more circuits to control transistors in addition to bit lines and word lines to further reduce the costs and to be more popular.